textproduct: Rapid City

KEY MESSAGES

- Accumulating and blowing snow overnight tonight through Thursday. Heaviest snow from northeastern Wyoming through southwestern South Dakota.

- Cold air filters in tonight with overnight lows in the single digits Thursday night through Saturday night.

- Warmer (above average) temperatures return next week.

UPDATE

Issued at 158 AM MST Thu Feb 19 2026

Compact vort max and associated sfc reflection continues to propagate through the region. Main FGEN associated lift will shift SE into NE this morning. Copious amounts of dry air have spread into the northern side of the system over western SD, with snowfall struggling to materialize east of the Black Hills. Given these concerns supported by hires model trends, which indicate a sharp cut off in snow amounts, have trimmed the adv in western SD.

DISCUSSION

(Tonight Through Wednesday) Issued at 953 PM MST Wed Feb 18 2026

Upper level analysis shows upper shortwave trough stretching from the Northern Rockies through the Northern Plains. Water vapor and other IR bands show ample upper level ascent overspreading the forecast area as strongest axis of DCVA lifts northward. Surface cyclogenesis is ongoing with a diffuse low pressure center forming over far NE CO and SW NE with a warm front stretching through central NE. Surface high pressure is pushing through SE Alberta with much colder air spilling into the forecast area.

As upper level ascent continues to overspread the region, snow chances will increase overnight. As was the case last night, considerable spread remains among the deterministic and ensemble guidance, even despite the event onset only a few hours away. I mentioned last night that the models were converging on two main, yet quite different, outcomes: 1) more snow pushing further northeast into our forecast area, and 2) a much drier solution, with the best axis of snow shunted off into NE WY and far SW SD. As it stands, the trend continues to concentrate the best snowfall potential from NE WY through the Black Hills into SW SD (outcome #2), with a very sharp cut off in snow amounts from Alzada, MT through the I-90 corridor in western SD. Currently have 3-6" in NE WY, the central and southern Hills, and SW SD with locally higher amounts possible under any heavier bands where the best focused ascent will be located. Dry air and weaker ascent will limit accumulations across the northeastern half of the forecast area. Overall, current headlines look reasonable with blowing snow a concern in addition to snow accumulation through Thursday.

Cold air will linger through the weekend with overnight lows in the single digits to near 0F. Upper ridging will return to the western half of the country late Sunday into Monday with temperatures warming back into the 40s and 50s for at least the first half of next week.

AVIATION

(For the 12Z TAFS Through 12Z Friday Morning) Issued At 425 AM MST Thu Feb 19 2026

MVFR/IFR conditions can be expected in areas of snow, particularly from KGCC into far SW SD through this afternoon. Dry air will limit eastward extent of the snow with only transient MVFR conditions expected at KRAP. Snow will end this evening with MVFR cigs lingering INVOF of the Black Hills and far western SD. Conds will trend VFR later tonight west to east.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Winter Weather Advisory until 5 PM MST this afternoon for SDZ024- 025-027>029-041-074>076. WY...Winter Weather Advisory until 5 PM MST this afternoon for WYZ057- 060. Winter Weather Advisory until 11 AM MST this morning for WYZ054- 056-058-059. Winter Storm Warning until 11 AM MST this morning for WYZ055.